WO2023219017A1 - Carrosserie d'automobile et son procédé de fabrication - Google Patents

Carrosserie d'automobile et son procédé de fabrication Download PDF

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Publication number
WO2023219017A1
WO2023219017A1 PCT/JP2023/016906 JP2023016906W WO2023219017A1 WO 2023219017 A1 WO2023219017 A1 WO 2023219017A1 JP 2023016906 W JP2023016906 W JP 2023016906W WO 2023219017 A1 WO2023219017 A1 WO 2023219017A1
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WIPO (PCT)
Prior art keywords
coating film
less
glitter
angle
mass
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PCT/JP2023/016906
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English (en)
Japanese (ja)
Inventor
貴和 山根
圭一 岡本
浩司 寺本
隆治 野中
健志 丸王
浩 清永
Original Assignee
マツダ株式会社
日本ペイント・オートモーティブコーティングス株式会社
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Publication of WO2023219017A1 publication Critical patent/WO2023219017A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/36—Successively applying liquids or other fluent materials, e.g. without intermediate treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D5/00—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
    • B05D5/06—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures to obtain multicolour or other optical effects
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/24—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials for applying particular liquids or other fluent materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • B32B27/20—Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02—Physical, chemical or physicochemical properties
    • B32B7/023—Optical properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D25/00—Superstructure or monocoque structure sub-units; Parts or details thereof not otherwise provided for
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D29/00—Superstructures, understructures, or sub-units thereof, characterised by the material thereof
    • B62D29/04—Superstructures, understructures, or sub-units thereof, characterised by the material thereof predominantly of synthetic material

Definitions

  • the present invention relates to an automobile body and a manufacturing method thereof.
  • Patent Documents 1 and 2 disclose a method of forming a coating film having a bright feeling and clear whiteness.
  • An object of the present invention is to provide an automobile body that is both white and has a metallic texture, and a method for manufacturing the same.
  • An automobile body comprising an object to be coated and a multilayer coating film
  • the multilayer coating film is a colored coating film formed on the object to be coated and containing a white pigment
  • a glittering coating film formed on the colored coating film and containing a glittering material
  • a clear coating film formed on the glitter coating film
  • the lightness L * 5 is based on the spectral reflectance of the light I 45 received at an angle of 5 degrees with respect to the specularly reflected light, and the spectral value of the light I 45 received at an angle of 15 degrees with respect to the specularly reflected light.
  • the ratio of lightness L * 15 based on reflectance: L * 5/L * 15 is 1.2 or more and 2.5 or less,
  • the occupancy rate of the glittering material viewed from the surface of the multilayer coating film is 10% or more and 30% or less,
  • the automobile body, wherein the particle texture on the surface of the multilayer coating film is 1.0 or more and 3.0 or less.
  • the lightness CL * 45 based on the spectral reflectance of the light IC 45 irradiated at an angle of 45 degrees to the surface of the colored coating film and received at an angle of 45 degrees with respect to the specularly reflected light is 70 or more and 95 or less.
  • the glitter material includes a scale-like glitter pigment having a thickness of 0.05 ⁇ m or more and 0.3 ⁇ m or less.
  • the lightness L * 5 is based on the spectral reflectance of the light I 45 received at an angle of 15 degrees with respect to the specularly reflected light, and the spectral value of the light I 45 received at an angle of 15 degrees with respect to the specularly reflected light.
  • the ratio of lightness L * 15 based on reflectance: L * 5/L * 15 is 1.2 or more and 2.5 or less,
  • the occupancy rate of the glittering material viewed from the surface of the multilayer coating film is 10% or more and 30% or less,
  • FIG. 1 is a cross-sectional view schematically showing an automobile body according to an embodiment of the present invention.
  • FIG. 1 is a cross-sectional view schematically showing a glitter coating film according to an embodiment of the present invention.
  • 1 is a flowchart showing a method for manufacturing an automobile body according to an embodiment of the present invention.
  • A. Automobile Body constitutes at least a part of an automobile.
  • An automobile body includes an object to be coated and a multilayer coating film.
  • a multi-layer coating film consists of a colored coating film formed on the object to be coated and containing a white pigment, a glittering coating film formed on the colored coating film and containing a glittering material, and a glittering coating film formed on the glittering coating film. and a clear coating film.
  • the flip-flop value (FF value) near the regularly reflected light is increased.
  • the FF value is an index indicating the change in brightness when the composite coating film is viewed from multiple directions.
  • the larger the FF value the larger the brightness difference.
  • by increasing the FF value in the vicinity of specularly reflected light the metallic texture in super highlights is enhanced.
  • the light I45 irradiated at an angle of 45 degrees (°) to the surface of the multilayer coating film is set at an angle of 5 degrees with respect to the specularly reflected light.
  • L * 5/L * 15 is 1.2 or more and 2.5 or less. When L * 5/L * 15 is within this range, the brightness change in highlights becomes large.
  • L * 5/L * 15 is preferably 1.30 or more, more preferably 1.35 or more.
  • L * 5/L * 15 is preferably 2.40 or less, more preferably 2.20 or less.
  • the super highlight is an area from -10 degrees to 10 degrees with respect to specularly reflected light (angle of 0 degrees).
  • the lightness L * 5 is calculated from the spectral reflectance of the above light I45 received at an angle of 5 degrees with respect to the specularly reflected light using the L * a * b * color system (CIE1976L * a * b * color space).
  • the lightness L * is at .
  • the lightness L * 15 is the lightness L * in the L * a * b * color system calculated from the spectral reflectance when the light I 45 is received at an angle of 15 degrees with respect to the specularly reflected light.
  • the lightness L * 45 described later is the lightness L * in the L * a * b * color system calculated from the spectral reflectance of the light I45 received at an angle of 45 degrees with respect to the specularly reflected light.
  • the lightness values L * 5, L * 15, and L * 45 can all take values of 0 or more.
  • the lightness L * can be obtained using a variable angle color difference meter (for example, Gonio-Spectrophotometer GSP-1, manufactured by Murakami Color Material Research Institute, Inc.).
  • the lightness L * is the average value of the lightness L * of five different samples.
  • the lightness L * 5 is not particularly limited.
  • the lightness L * 5 is preferably 120 or more, and more preferably 150 or more, in terms of enhancing the brightness.
  • the lightness L * 15 is also not particularly limited. Lightness L * 15 may be 90 or more, and may be 100 or more. Since the FF value tends to increase, the lightness L * 15 is preferably 150 or less, more preferably 130 or less.
  • the value obtained by subtracting the lightness L * 15 from the lightness L * 5 is, for example, 40 or more, preferably 45 or more, and more preferably 50 or more.
  • FIG. 1 is a diagram illustrating the light receiving angle of spectral reflectance.
  • the specular reflection of light I 45 irradiated at an angle of 45 degrees with respect to the surface of the multilayer coating is indicated by R 0 .
  • the light received at an angle of 5 degrees relative to the specular reflection of light I 45 is designated R 5 .
  • Light received at an angle of 15 degrees to the specular reflection of light I 45 is designated R 15 .
  • Light received at a 45 degree angle to the specular reflection of light I 45 is designated R 45 .
  • the graininess (hereinafter referred to as graininess G) of the multilayer coating film is small.
  • the grain feel is 1.0 or more and 3.0 or less.
  • Grain feel G is preferably 1.5 or more, more preferably 1.8 or more.
  • the grain feel G is preferably 2.7 or less, more preferably 2.3 or less.
  • the grain feel G is obtained by taking an image of a composite coating film irradiated with diffused light and analyzing it using a specific image analysis algorithm. Specifically, the composite coating film is irradiated with diffused light from a light source installed in a white-painted hemisphere. It is obtained by taking an image of the composite coating film from its normal direction with a CCD camera and analyzing it using a specific image analysis algorithm. Grain feel G can be obtained using a multi-angle colorimeter (for example, BYK-mac i, manufactured by BYK-Gardner). Grain feel G * is the average value of grain feel G of five different samples.
  • the occupancy rate of the glitter material as seen from the surface of the multilayer coating is 10% or more and 30% or less. Thereby, the white pigment contained in the colored coating film can be visually recognized without passing through the glitter material. Therefore, the brightness in the shade becomes higher.
  • the occupancy rate of the bright material is preferably 13% or more, more preferably 16% or more.
  • the occupancy rate of the bright material is preferably 23% or less, more preferably 20% or less. In this embodiment, the grain feel G is kept low. Therefore, even if the occupancy rate of the glitter material is reduced, the metallic texture can be enhanced.
  • the occupancy of the glittering material is the area ratio of the glittering material in the multilayer coating film when viewed from the normal direction.
  • the multilayer coating film is observed using an electron microscope from its normal direction.
  • the area corresponding to the glitter material and the other area are binarized using image processing software.
  • the area ratio of the glittering material is calculated by setting the area of the observation visual field to 100%.
  • the magnification of the electron microscope is not particularly limited, and may be, for example, about 100 times or more and 200 times or less.
  • the size of the observation field is also not particularly limited, and may be, for example, about 500 nm or more and 1000 nm or less vertically, and about 1000 nm or more and 1500 nm or less horizontally.
  • an industrial microscope for example, ECLIPSE LV150N manufactured by Nikon Instech Co., Ltd.
  • image processing software for example, NIS-Elements (manufactured by Nikon Corporation, general image software) and NIS-A AMEAS (manufactured by Nikon Corporation, software for distance measurement and area calculation) are used.
  • the occupancy rate is the average value of the occupancy rates in five different observation fields.
  • the lightness L * 45 based on the spectral reflectance when the light I 45 is received at an angle of 45 degrees with respect to the specularly reflected light is 70 or more and 90 or less.
  • the lightness L * 45 is preferably 73 or more, more preferably 75 or more.
  • the lightness L * 45 is preferably 87 or less, more preferably 85 or less.
  • the glitter coating film includes a glitter material arranged in parallel to the coating film.
  • 80% or more of the glittering materials contained in the glittering coating film are arranged parallel to the surface of the multilayer coating film.
  • Parallel means that in the cross section of the multilayer coating film, the acute angle ⁇ between the surface of the glitter coating film and the glitter material is 0 degrees or more and 30 degrees or less.
  • the arrangement of the glitter materials is indicated, for example, by the sparkle intensity of the multilayer coating.
  • the Si 15 value of the composite coating can be 3.0 or more and 4.0 or less. When the Si 15 value is within this range, it can be said that 80% or more of the number of glitter materials contained in the glitter coating film are arranged parallel to the surface of the glitter coating film.
  • the Si 15 value is preferably 3.1 or more, more preferably 3.2 or more.
  • the Si 15 value is preferably 3.8 or less, more preferably 3.6 or less.
  • the Si 15 value is determined by capturing an image from the normal direction of the multi-layer coating film using light irradiated from a direction tilted 15 degrees with respect to the normal direction of the multi-layer coating film, and analyzing it using a specific image analysis algorithm. It will be done.
  • the image analysis algorithm uses a histogram of brightness levels.
  • the Si 15 value can be obtained using a multi-angle colorimeter (for example, BYK-mac i, manufactured by BYK-Gardner).
  • the Si 15 value is the average of the Si 15 values of five different samples.
  • the arrangement of the scaly glittering pigment (hereinafter referred to as scaly glittering material) can also be confirmed from the cross section of the multilayer coating film.
  • the acute angle ⁇ is determined from the cross section of the multilayer coating as follows. First, a cross-section of the multilayer coating film is imaged using an electron microscope. The obtained cross section is placed on two-dimensional coordinates (xy coordinates), and an approximate straight line L 0 of the surface of the glitter coating film is determined. Similarly, an approximate straight line L1 on the surface of the scaly glitter material is determined. The surface of the scaly glitter material is the main surface closer to the clear coating film. The angle formed by the approximate straight line L 0 and the approximate straight line L 1 is the angle ⁇ .
  • the proportion of scaly glittering materials that are parallel to the glittering coating film is determined by determining the number of scaly glittering materials that are arranged parallel to the glittering coating film and that can be seen in their entirety in the observation field. It is calculated by dividing by the number of bright materials that can be produced.
  • the magnification is not particularly limited.
  • the magnification of the electron microscope may be, for example, about 100 times or more and 200 times or less.
  • the size of the observation field is also not particularly limited, and may be, for example, about 500 nm or more and 1000 nm or less vertically, and about 1000 nm or more and 1500 nm or less horizontally. In the following observation using an electron microscope, the magnification and observation field may be the same as above.
  • the scale-like glitter materials do not overlap each other. This makes it easier for the scaly glitter material to be arranged in parallel with the glitter coating. Furthermore, even when the occupancy rate of the glittering material is low, the coating film gives a strong impression of being dense and has a metallic texture.
  • the expression that the scaly glitter materials do not overlap with each other means that in the cross section of the multilayer coating film, part or all of the scaly glitter materials and other scaly glitter materials do not overlap in the thickness direction. It is not necessary that the scaly bright materials are in contact with each other. For example, when a multilayer coating film is viewed from the normal direction, if some or all of the scaly glitter materials appear to overlap, the scaly glitter materials overlap in the thickness direction.
  • the scale-like glitter materials contained in the glitter coating film do not overlap with other scale-like glitter materials.
  • the overlapping ratio of the scaly glitter material is determined as follows. First, a cross-section of the multilayer coating film is imaged using an electron microscope. In the obtained cross section, one or more scale-like glitter materials located closest to the clear coating film of the glitter coating film are used as reference glitter materials. Mark the scale-like bright material that overlaps the reference bright material in the thickness direction. Furthermore, a mark is placed on the scale-like bright material that overlaps the marked scale-like bright material in the thickness direction.
  • Count all the scale-like bright materials (hereinafter sometimes referred to as duplicate bright materials) that are marked and can be seen in their entirety in the observation field. At this time, avoid counting one duplicate glitter material multiple times.
  • the proportion of overlapping bright materials is determined by dividing the number of overlapping bright materials by the number of scale-like bright materials that can be seen in their entirety in the observation field (i.e., the total of the reference bright materials and the overlapping bright materials).
  • the material to be coated is not particularly limited as long as it is suitable for automobile bodies.
  • Examples of the object to be coated include metal materials containing iron, copper, aluminum, tin, zinc, or alloys thereof.
  • the shape of the object to be coated is also not particularly limited.
  • the object to be coated may be plate-shaped or may have a three-dimensional shape.
  • the object to be coated constitutes, for example, at least a portion of a vehicle body such as a passenger car, truck, or bus.
  • the object to be coated may be degreased and/or surface treated.
  • the surface treatment include phosphate treatment, chromate treatment, zirconium chemical conversion treatment, and complex oxide treatment.
  • the metal material is preferably coated with an undercoat using an electrodeposition paint.
  • the electrodeposition paint may be of the cationic type or the anionic type.
  • the multilayer coating film includes a colored coating film, a glitter coating film, and a clear coating film in this order.
  • the specular gloss of the multilayer coating film is not particularly limited.
  • the 60 degree specular gloss of the multilayer coating may be 100% or more and 180% or less.
  • the 60 degree specular gloss is measured in accordance with JIS Z 8741 Specular Gloss - Measuring Method. Specifically, light is irradiated at an incident angle of 60 degrees with respect to the normal line of the multilayer coating film, and the luminous flux ⁇ S of the reflected light at a reflection angle of 60 degrees is measured. Under the same conditions, a flat surface of glass with a refractive index of 1.567 is irradiated with light, and the luminous flux ⁇ 0 of the reflected light is measured. The value obtained by dividing the luminous flux ⁇ S by the luminous flux ⁇ 0 and multiplying it by 100 is the 60 degree specular gloss.
  • the 60 degree specular gloss is the average value of the 60 degree specular gloss of five different samples.
  • ⁇ Colored coating film> The colored coating hides the texture and color of the object being coated and provides a white tone to the automobile body.
  • the thickness of the colored coating film is not particularly limited. From the viewpoint of hiding properties, the thickness of the colored coating film may be 15 ⁇ m or more and 50 ⁇ m or less, 18 ⁇ m or more and 45 ⁇ m or less, and 20 ⁇ m or more and 40 ⁇ m or less. When the thickness of the colored coating film is within this range, the texture and color of the object to be coated are likely to be hidden without being visible through the colored coating film.
  • the thickness of the colored coating film is measured using, for example, an electromagnetic film thickness meter.
  • the thickness of the colored coating film is the average value of the thickness of the colored coating film in five different samples. The thicknesses of other layers can be similarly measured and calculated.
  • the black and white concealing film thickness of the colored coating film is preferably 80 ⁇ m or less, more preferably 10 ⁇ m or more and 70 ⁇ m or less, particularly preferably 15 ⁇ m or more and 60 ⁇ m or less.
  • the black and white hiding film thickness is measured using a black and white checkered pattern hiding rate test paper specified in 4.1.2 of JIS K5600-4-1. Specifically, a concealment rate test paper is pasted on a steel plate, and the paint is applied diagonally so that the film thickness changes continuously. After the paint is dry or cured, visually inspect the painted surface under diffused daylight. The minimum film thickness at which the black and white border of the checkered pattern on the hiding rate test paper becomes invisible is the black and white hiding film thickness. This film thickness can also be measured using an electromagnetic film thickness meter.
  • the lightness CL * 45 is preferably 70 or more and 95 or less based on the spectral reflectance when the light IC 45 is irradiated at an angle of 45 degrees with respect to the surface of the colored coating film and is received at an angle of 45 degrees with respect to the specularly reflected light. . Due to the high lightness of the colored coating in the shade and the small occupancy of the glitter material, the multilayer coating appears whiter in the area on the shade side than the super highlights.
  • the colored coating film contains a white pigment.
  • the white pigment is not particularly limited. Examples of white pigments include titanium dioxide, zinc oxide, and silica. These may be used alone or in combination of two or more. Titanium dioxide is preferred because it has a high refractive index. Titanium dioxide may be of rutile type or anatase type. Among these, rutile-type titanium dioxide is preferred from the viewpoint of weather resistance.
  • the surface of titanium dioxide may be treated with an inorganic compound such as silica, zirconium, or aluminum.
  • the primary particle size of the white pigment is not particularly limited. From the viewpoint of hiding performance, the primary particle diameter of the white pigment is preferably 100 nm or more and 500 nm or less, more preferably 200 nm or more and 400 nm or less. The primary particle diameter can be measured using image processing software from an electron microscope image of a cross section of the multilayer coating film.
  • the amount of white pigment is not particularly limited.
  • the white pigment is added so that the lightness L * 45 is 70 or more and 90 or less.
  • the white pigment is preferably added so that the lightness CL * 45 of the colored coating film is 70 or more and 95 or less.
  • the amount of the white pigment is preferably 5% by mass or more and 40% by mass or less of the colored coating film, more preferably 10% by mass or more and 30% by mass or less, and even more preferably 15% by mass or more and 25% by mass or less.
  • the amount of the white pigment is preferably 50 parts by mass or more and 200 parts by mass or less, more preferably 80 parts by mass or more and 150 parts by mass or less, based on 100 parts by mass of the first resin described below.
  • the colored coating film contains, for example, a first resin as a vehicle in addition to the white pigment.
  • a white pigment is dispersed in the first resin.
  • the first resin is not particularly limited.
  • the first resin preferably includes a cured product of the first thermosetting resin.
  • the first resin is obtained, for example, by curing a first thermosetting resin formed from a crosslinkable functional group and a base resin.
  • a first curing agent may be used for curing.
  • crosslinkable functional group examples include a carboxy group, a hydroxyl group, an epoxy group, a silanol group, and a (meth)acryloyl group.
  • the base resin examples include acrylic resin, polyester resin, alkyd resin, polyurethane resin, epoxy resin, and fluororesin.
  • the epoxy resin may be a urethane modified epoxy resin.
  • the polyester resin may be a urethane modified polyester resin.
  • the acrylic resin may be a urethane-modified acrylic resin. Each urethane modified resin has urethane bonds in the resin skeleton. These may be used alone or in combination of two or more. Among these, acrylic resins and urethane-modified polyesters are preferred in terms of improved chipping resistance.
  • Acrylic resins include, for example, ⁇ , ⁇ -ethylenically unsaturated carboxylic acids, (meth)acrylic esters having functional groups such as hydroxyl groups, amide groups, and methylol groups, other (meth)acrylic esters, and styrene. Obtained by polymerization.
  • Urethane-modified polyester is obtained by reacting a hydroxyl group-containing polyester with an aliphatic diisocyanate compound.
  • the hydroxyl group-containing polyester is prepared by polycondensing an acid component such as a polycarboxylic acid and/or an acid anhydride with a polyhydric alcohol.
  • the aliphatic diisocyanate compound include hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4-diisocyanate, and methylcyclohexane diisocyanate.
  • the amount of the first resin is not particularly limited. In terms of easily forming a uniform coating film, the amount of the first resin is preferably 60% by mass or more and 95% by mass or less of the colored coating film, more preferably 70% by mass or more and 90% by mass or less, and 75% by mass or more and 85% by mass or less. It is more preferably less than % by mass.
  • the glass transition temperature (Tg) of the first resin is not particularly limited. From the viewpoint of coating film hardness and smoothness, the Tg of the first resin is preferably -40°C or more and 20°C or less, more preferably -30°C or more and 10°C or less. Tg is measured by a differential scanning calorimeter (DSC) based on JIS K 7121.
  • DSC differential scanning calorimeter
  • the colored coating film may further contain other pigments depending on the hiding property and the like.
  • other pigments include metallic pigments, antirust pigments, colored pigments other than white pigments, and extender pigments.
  • extender pigments include calcium carbonate, barium sulfate, clay, and talc.
  • the colored coating film may also contain various additives as necessary.
  • additives include ultraviolet absorbers, antioxidants, antifoaming agents, surface conditioners, dispersants, and pinhole inhibitors.
  • Glitter coatings give automobile bodies a metallic texture.
  • the thickness of the glitter coating film is not particularly limited.
  • the thickness of the glitter coating film is preferably 0.05 ⁇ m or more and 1.0 ⁇ m or less, since the glitter material is likely to be arranged in parallel with the coating film.
  • the thickness of the glitter coating film may be 0.1 ⁇ m or more, and may be 0.3 ⁇ m or more.
  • the thickness of the glitter coating film may be 0.8 ⁇ m or less, and may be 0.7 ⁇ m or less.
  • the glitter coating film contains a glitter material.
  • the glitter material is not particularly limited as long as it reflects light. Among these, scaly glitter materials are preferred because they can make the glitter coating film thinner and can easily improve the metallic texture.
  • the aspect ratio of the scaly glittering material is, for example, 2 or more. The aspect ratio is the ratio of the major axis of one principal surface of the glittering scale material to the distance (thickness) between the two principal surfaces of the glittering flake material: major axis/thickness.
  • the aspect ratio of the scaly glitter material may be 10 or more and 1000 or less.
  • the glittering coating film may contain a glittering material other than the flaky glittering material (a glittering material having an aspect ratio of less than 2) together with the flaky glittering material.
  • a glittering material other than the flaky glittering material a glittering material having an aspect ratio of less than 2
  • the content of other glittering materials is preferably 10% by mass or less, and preferably 5% by mass or less of the total glittering materials. This makes it easier for the scaly glitter material to be arranged parallel to the coating film.
  • the long axis of the glitter material is not particularly limited. In terms of easy adjustment of the occupancy, the long axis of the glittering material is preferably 1 ⁇ m or more and 80 ⁇ m or less, and preferably 3 ⁇ m or more and 50 ⁇ m or less.
  • the above-mentioned major axis is calculated by observing the multilayer coating film from the normal direction with an electron microscope. In the observation field, the area corresponding to the glitter material and the other area are binarized using image processing software. Next, 20 bright materials are arbitrarily selected and the longest diameter of each is measured. The average value of these measured values is the major axis of the glitter material.
  • the thickness of the glittering material is preferably 0.05 ⁇ m or more and 0.3 ⁇ m or less. This allows the glitter coating to be made thinner.
  • the thickness of the glitter material is preferably 0.25 ⁇ m or less, more preferably 0.2 ⁇ m or less.
  • the above thickness may be calculated by observing the cross section of the multilayer coating film with an electron microscope. In the observation field, the area corresponding to the glitter material and the other area are binarized using image processing software. Next, 20 glittering materials are randomly selected and the lengths of their thickest parts are measured. The average value of these measured values is the thickness of the glitter material.
  • the average particle diameter of the glitter material is not particularly limited.
  • the average particle diameter of the glittering material is preferably 2 ⁇ m or more and 50 ⁇ m or less, and preferably 5 ⁇ m or more and 35 ⁇ m or less, since the glitter feeling is easily improved.
  • the average particle diameter means the volume average particle diameter D50.
  • the volume average particle diameter D50 can be measured using a laser Doppler particle size analyzer (for example, "Microtrac UPA150" manufactured by Nikkiso Co., Ltd.).
  • the bright material is not particularly limited. Since L * 5/L * 15 tends to be large, a glittering material that does not use multiple reflection interference as a coloring function is preferable. Examples of such glittering materials include metal particles. Specific examples include particles of aluminum, copper, zinc, iron, nickel, tin, aluminum oxide, and alloys containing these. The glitter material may be colored. These may be used alone or in combination of two or more. Mica is a typical luminescent material whose coloring function is based on multiple reflection interference. Even when using metal particles with high reflectance, a high lightness L * 45 can be achieved by keeping the occupancy low.
  • Scale-shaped aluminum particles are more preferable because a high brightness can be obtained with a small amount.
  • the amount of the total glitter material is preferably 3% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 25% by mass or less of the glitter coating film. As a result, the occupancy rate of the glitter material tends to be 10% or more and 30% or less.
  • the glitter coating film may also contain a viscosity modifier.
  • the viscosity modifier adjusts the viscosity of the glitter pigment dispersion (Y), which is a material for the glitter coating film.
  • the glitter material In the glitter pigment dispersion (Y) immediately after coating, the glitter material is arranged parallel to the coating film. However, when the liquid component contained in the glitter pigment dispersion (Y) flows, the glitter material also flows and its arrangement becomes disordered.
  • the viscosity of the glitter pigment dispersion (Y) in the glitter coating film after application and before curing, the flow of the liquid component is suppressed, and the disorder of the arrangement of the glitter material is also suppressed. . Therefore, the glitter material is easily held in a state in which it is arranged parallel to the coating film.
  • the viscosity modifier is not particularly limited.
  • examples of the viscosity modifier include silica-based fine powder, mineral-based viscosity modifier, barium sulfate micronized powder, polyamide-based viscosity modifier, organic resin fine particle viscosity modifier, diurea-based viscosity modifier, and urethane-based viscosity modifier. , an acrylic swelling type polyacrylic acid viscosity modifier, and a cellulose viscosity modifier. These may be used alone or in combination of two or more. Among these, cellulose-based viscosity modifiers are preferred because the glittering material is easily dispersed and they have excellent quick drying properties.
  • mineral-based viscosity modifiers include swellable layered silicates having a 2:1 crystal structure. Specifically, smectite group clay minerals such as natural or synthetic montmorillonite, saponite, hectorite, stevensite, beidellite, nontronite, bentonite, and laponite; Na-type tetrasilicic fluorinated mica, Li-type tetrasilicic fluorinated mica, Swellable mica group clay minerals such as Na salt type fluorine taeniolite and Li type fluorine taeniolite; vermiculite; substitution products and derivatives thereof.
  • smectite group clay minerals such as natural or synthetic montmorillonite, saponite, hectorite, stevensite, beidellite, nontronite, bentonite, and laponite
  • Na-type tetrasilicic fluorinated mica Li-type tetrasilicic fluorinated mica
  • polyacrylic acid-based viscosity modifier examples include sodium polyacrylate and polyacrylic acid-(meth)acrylic acid ester copolymer.
  • Commercially available polyacrylic acid-based viscosity modifiers include, for example, Primal ASE-60, Primal TT615, Primal RM5 (all manufactured by The Dow Chemical Company), SN Thickener 613, SN Thickener 618, SN Thickener 630, SN Thickener 634, Examples include SN Thickener 636 (all manufactured by San Nopco).
  • the solid content acid value of the polyacrylic acid-based viscosity modifier is not particularly limited. The solid content acid value may be 30 mgKOH/g or more and 300 mgKOH/g or less, and may be 80 mgKOH/g or more and 280 mgKOH/g or less.
  • cellulose-based viscosity modifiers examples include cellulose acetate butyrate (CAB), carboxymethylcellulose, methylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, methylcellulose, and cellulose nanofiber gel. These may be used alone or in combination of two or more. Among them, CAB is preferred.
  • the amount of the viscosity modifier is not particularly limited.
  • the amount of the viscosity modifier may be, for example, 0.1 parts by mass or more and 10 parts by mass or less, and 0.5 parts by mass or more and 5 parts by mass or less, based on 100 parts by mass of the glitter pigment dispersion. , 1.0 parts by mass or more and 3.0 parts by mass or less. This makes it easier to suppress the disorder in the arrangement of the glitter material.
  • the glitter coating film may include a resin component (second resin).
  • the second resin includes, for example, a cured product of the same thermosetting resin as the first resin. However, it is desirable that the amount of the second resin be small. By reducing the amount of the second resin, it becomes easy to make the glitter coating film thin. When the glittering coating film is thin, disordered orientation of the glittering material is more likely to be suppressed, and the glittering material is more likely to be aligned parallel to the surface of the coating film.
  • the amount of the second resin is preferably 15% by mass or less of the glitter pigment dispersion, more preferably 10% by mass or less, and particularly preferably 5% by mass or less, since a thin glitter coating film is easily formed.
  • the glitter coating film may contain pigments other than the glitter material depending on the hiding property and the like.
  • Other pigments include, for example, antirust pigments, colored pigments (including white pigments), and the above-mentioned extender pigments.
  • the glitter coating film may contain a white pigment (particularly titanium dioxide).
  • the content of other pigments (particularly titanium dioxide) is preferably 10% by mass or less of the glitter pigment dispersion, and preferably 2% by mass or less, in that the scale-like glitter material is easily arranged in parallel with the coating film. .
  • the content of other pigments (particularly titanium dioxide) may be 0.01% by mass or more of the glitter pigment dispersion, and may be 0.1% by mass or more.
  • the glitter coating film may contain various additives as necessary.
  • additives include ultraviolet absorbers, antioxidants, antifoaming agents, antisettling agents, dispersants, and surface conditioners.
  • the clear coating protects the colored coating and the glitter coating.
  • the clear coating film is not particularly limited, and has the same structure as a conventionally known clear coating film.
  • the thickness of the clear coating film is not particularly limited. From the viewpoint of scratch resistance, the thickness of the clear coating film is preferably 10 ⁇ m or more, more preferably 15 ⁇ m or more. The thickness of the clear coating film may be 50 ⁇ m or less, and may be 40 ⁇ m or less, in that the whiteness and metallic texture are not easily impaired.
  • the clear coating film contains, for example, a third resin. It is preferable that the third resin includes a cured product of the third thermosetting resin. Specifically, the third resin is obtained by curing a third thermosetting resin formed from a crosslinkable functional group and a base resin. A second curing agent may be used for curing.
  • thermosetting resin examples include the same resins as those exemplified as the first thermosetting resin.
  • the Tg of the third resin is not particularly limited. From the viewpoint of coating film hardness and smoothness, the Tg of the third resin is preferably -40°C or more and 20°C or less, more preferably -30°C or more and 10°C or less.
  • the clear coating film may contain pigments to the extent that transparency is not impaired.
  • the pigment is not particularly limited, and conventionally known pigments can be used alone or in combination of two or more.
  • the amount of pigment added is not particularly limited. The amount of the pigment added is, for example, 30 parts by mass or less, and may be 0.01 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of the solid content of the third resin.
  • the clear coating film may contain various additives as necessary.
  • additives include ultraviolet absorbers, antioxidants, antifoaming agents, surface conditioners, and anti-pinhole agents.
  • FIG. 2 is a sectional view schematically showing a part of the automobile body according to the present embodiment.
  • the automobile body 100 includes an object to be coated 10 and a multilayer coating film 20.
  • the multilayer coating film 20 includes a colored coating film 21, a glittering coating film 22, and a clear coating film 23 in this order.
  • the glitter coating film 22 includes a glitter material 221 .
  • FIG. 3 is a cross-sectional view schematically showing a part of the glitter coating film in this embodiment.
  • the acute angle between the approximate straight line L 0 on the surface of the glitter coating film 22 and the approximate straight line L 1 on the surface of the glitter material 221 is approximately 0 degrees. That is, the glitter material 221 is parallel to the surface of the glitter coating film 22.
  • An automobile body is manufactured by forming a colored coating film, a glittering coating film, and a clear coating film in this order on an object to be coated.
  • the colored coating may be cured or uncured.
  • the clear coating film is formed, the glitter coating film may be cured or uncured.
  • curing is a concept that includes solidification. That is, curing in this specification means that the coating film loses fluidity, regardless of whether a chemical reaction is involved or not.
  • curing in this specification has the same meaning as "curing and drying" defined in JIS K 5500 (coating terminology).
  • curing is confirmed by a) pinching the center of the test piece firmly between your thumb and forefinger, and making sure that there are no dents on the painted surface due to fingerprints, no movement of the paint film, and that the painted surface is quickly touched with your fingertips. This refers to a condition in which no scratches remain after repeated rubbing (dry hard).
  • uncured refers to a state other than the above-mentioned cured state, and includes a semi-cured state.
  • the automobile body is preferably manufactured by the following method.
  • the method for manufacturing an automobile body includes a step of coating a colored paint on an object to be coated to form an uncured colored coating film, and a step of coating a bright pigment dispersion on the uncured colored coating film. a process of forming an uncured glitter coating film, a process of coating a clear paint on the uncured glitter coating film to form an uncured clear coating film, and a process of forming an uncured colored coating film and an uncured coating film.
  • the method includes the step of curing the cured glitter coating film and the uncured clear coating film to obtain a multilayer coating film.
  • FIG. 4 is a flowchart showing a method for manufacturing an automobile body according to this embodiment.
  • Lightness L * 45 based on the spectral reflectance of light I 45 irradiated at a 45 degree angle to the surface of the multilayer coating film to be formed and received at a 45 degree angle to specularly reflected light is 70 or more. 80 or less.
  • the lightness L * 5 is based on the spectral reflectance when the above light I 45 is received at an angle of 15 degrees with respect to the specularly reflected light, and the above light I 45 is received at an angle of 15 degrees with respect to the specularly reflected light.
  • the ratio to the lightness L * 15 based on the spectral reflectance: L * 5/L * 15 is 1.2 or more and 2.5 or less.
  • the occupancy rate of the glitter material as viewed from the surface of the multilayer coating is 10% or more and 30% or less.
  • the particle feel G on the surface of the multilayer coating is 1.0 or more and 3.0 or less.
  • Step of forming an uncured colored coating film S11
  • a colored paint (X) is applied onto an object to form an uncured colored paint film.
  • the coating method is not particularly limited.
  • Examples of the coating method include air spray coating, airless spray coating, rotary atomization coating, and curtain coating. These methods and electrostatic coating may be combined.
  • rotary atomization electrostatic coating is preferred from the viewpoint of coating efficiency.
  • Examples of rotary atomization electrostatic coatings include rotary atomization electrostatic coatings commonly known as "micro/microbell”, “microbell”, “metallic bell”, etc. A paint machine is used.
  • the amount of colored paint (X) applied is not particularly limited.
  • the colored coating material (X) is applied, for example, so that the thickness of the colored coating film after curing is 15 ⁇ m or more and 50 ⁇ m or less.
  • preliminary drying also referred to as preheating
  • preheating suppresses bumping of the solvent contained in the colored coating film during the curing process, making it easier to suppress the occurrence of wrinkles.
  • pre-drying suppresses mixing of the uncured colored coating film and the glitter paint, making it difficult to form a mixed layer. Therefore, the appearance of the obtained multilayer coating film is likely to be improved.
  • Pre-drying conditions are not particularly limited. Pre-drying includes, for example, a method of leaving the product at a temperature of 20° C. or more and 25° C. or less for 15 minutes or more and 30 minutes or less, or a method of heating at a temperature of 50° C. or more and 100° C. or less for 30 seconds or more and 10 minutes or less.
  • the colored paint (X) contains the above-mentioned white pigment and first thermosetting resin.
  • the colored paint (X) contains a first curing agent, a first solvent, various additives, and the like, if necessary.
  • the colored paint (X) is prepared by diluting a mixture of a white pigment, a first thermosetting resin, a first curing agent, various additives, etc. with a first solvent.
  • the colored paint (X) may be a one-component paint or a multi-component paint such as a two-component paint.
  • the viscosity of the colored paint (X) is not particularly limited.
  • the viscosity of the colored paint (X) measured at 20° C. using a B-type viscometer is, for example, 500 cps/6 rpm or more and 6000 cps/6 rpm or less.
  • the solid content of the colored paint (X) is not particularly limited.
  • the solid content of the colored paint (X) is preferably 30% by mass or more and 70% by mass or less.
  • the solid content of the colored paint (X) is the entire component of the colored paint (X) excluding the first solvent.
  • thermosetting resin The first thermosetting resin is formed from a crosslinkable functional group and a base resin. Details of the crosslinkable functional group and base resin are as described above.
  • the amount of the first thermosetting resin is not particularly limited.
  • the solid content mass of the first thermosetting resin is 60% by mass or more and 90% by mass of the total solid content mass of the first thermosetting resin and the solid content mass of the first curing agent. % or less, more preferably 70% by mass or more and 85% by mass or less.
  • the first curing agent is not particularly limited, and may be appropriately selected depending on the first thermosetting resin.
  • the first curing agent include amino resins, urea resins, polyisocyanate compounds, epoxy group-containing compounds, carboxy group-containing compounds, carbodiimide group-containing compounds, hydrazide group-containing compounds, and semicarbazide group-containing compounds.
  • the polyisocyanate compound includes a blocked polyisocyanate compound in which isocyanate groups are blocked with a blocking agent. These may be used alone or in combination of two or more. Among these, amino resins and polyisocyanate compounds are preferred from the viewpoint of various properties and cost of the resulting coating film.
  • the amino resin can be obtained, for example, by condensing an amino compound such as melamine, benzoguanamine or urea with formaldehyde, and further etherifying it with a lower monohydric alcohol. Details of the polyisocyanate compound will be described later.
  • the amount of the first curing agent is not particularly limited.
  • the solid content mass of the first curing agent is preferably 10% by mass or more and 40% by mass or less of the total solid content mass of the first thermosetting resin and the solid content mass of the first curing agent, and 15% by mass or less. It is more preferably 15% by mass or more and 25% by mass or less, particularly preferably 15% by mass or more and 25% by mass or less.
  • the first solvent is not particularly limited.
  • the first solvent may be water (deionized water), an organic solvent, or a combination thereof. Among them, water is preferred from the viewpoint of low VOC (Volatile Organic Compounds).
  • the proportion of water in the first solvent is preferably 50% by mass or more, and preferably 80% by mass or more.
  • organic solvents examples include ester solvents such as ethyl acetate, butyl acetate, isopropyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; Ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, methyl methoxybutanol, ethoxypropanol, ethylene glycol isopropyl ether, ethylene glycol-t-butyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, methoxybutanol, propylene glycol monobutyl ether Alcohol-based solvents such as methanol, ethanol, butanol, and propyl alcohol; Ketone-based solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; Aliphatic
  • the amount of the first solvent is not particularly limited, and is appropriately set depending on the solid content and viscosity of the colored paint (X).
  • the first solvent is such that the solid content of the colored paint (X) is 30% by mass or more and 70% by mass or less, and the viscosity of the colored paint (X) measured by a B-type viscometer at 20° C. is 500 cps/6 rpm. It is added so that the speed is 6000 cps/6 rpm or less.
  • a first thermosetting resin having a hydrophilic group When using water as the first solvent, a first thermosetting resin having a hydrophilic group may be used. By neutralizing the hydrophilic groups of the first thermosetting resin to form an alkali salt, the first thermosetting resin is made water-soluble or water-dispersible.
  • the hydrophilic group include a carboxy group, a hydroxyl group, a methylol group, an amino group, a sulfonic acid group, and a polyoxyethylene bond.
  • the neutralizing agent include alkaline substances such as sodium hydroxide and amine compounds.
  • the first thermosetting resin can be prepared in a water-dispersed state by emulsion polymerizing raw material monomers of the first thermosetting resin in the presence of a surfactant and a water-soluble resin.
  • the first thermosetting resin may be dispersed in water using an emulsifier.
  • the first thermosetting resin may not contain any hydrophilic groups, or may contain only a small amount of hydrophilic groups.
  • the colored paint (X) also contains the pigments and various additives exemplified as those contained in the colored paint film.
  • Step of forming an uncured glitter coating S12
  • a glittering pigment dispersion (Y) is applied onto the uncured colored coating film to form an uncured glittering coating film.
  • the coating method is not particularly limited. Examples of the coating method include methods similar to those for colored paints. Among these, rotary atomization electrostatic coating is preferred from the viewpoint of coating efficiency.
  • the coating amount of the glitter pigment dispersion (Y) is not particularly limited.
  • the glittering pigment dispersion (Y) is applied, for example, so that the thickness of the glittering coating in the resulting multilayer coating is 0.05 ⁇ m or more and 1.0 ⁇ m or less.
  • the conditions for pre-drying are not particularly limited and may be the same as those for pre-drying a colored coating film.
  • the glitter pigment dispersion (Y) contains a glitter material.
  • the bright pigment dispersion (Y) contains a viscosity modifier, a second solvent, and the like, if necessary.
  • the glitter pigment dispersion (Y) is prepared by diluting a mixture of a glitter material, a viscosity modifier, various additives, etc. with a second solvent.
  • the viscosity of the glitter pigment dispersion (Y) is not particularly limited.
  • the viscosity of the glittering pigment dispersion (Y) is preferably 20 cps/6 rpm or more and 3000 cps/6 rpm or less, as measured by a B-type viscometer at 20° C., since disorder of the arrangement of the glitter material is easily suppressed. .
  • the solid content of the bright pigment dispersion (Y) is preferably 0.1% by mass or more and 10.0% by mass or less. This makes it easy to form a thin glitter coating.
  • the solid content of the bright pigment dispersion (Y) is preferably 9.0% by mass or less, more preferably 8.0% by mass or less, particularly preferably 7.5% by mass or less.
  • the solid content of the glitter pigment dispersion (Y) is the entire component of the glitter pigment dispersion (Y) excluding the second solvent.
  • the solid content of the glitter pigment dispersion (Y) is 3.5. It is preferably at least 4.0% by mass, more preferably at least 4.5% by mass, and particularly preferably at least 4.5% by mass.
  • the solid content of the glitter pigment dispersion (Y) is preferably 8.5% by mass or less, more preferably 8.0% by mass or less, and 7.5% by mass or less. Particularly preferably less than % by mass.
  • the solid content of the bright pigment dispersion (Y) is 1.0 mass%. % or more is preferable, and 2.0 mass % or more is more preferable.
  • the solid content of the glitter pigment dispersion (Y) is preferably 5.0% by mass or less, more preferably 3.5% by mass or less.
  • the amount of glitter material is not particularly limited.
  • the amount of the glittering material may be, for example, 0.05% by mass or more and 3.0% by mass or less, or 0.2% by mass or more and 1.5% by mass or less of the glittering pigment dispersion (Y). , 0.3% by mass or more and 0.8% by mass or less.
  • the occupancy rate of the glitter material tends to be 10% or more and 30% or less.
  • viscosity modifier Details of the viscosity modifier are as described above.
  • the amount of the viscosity modifier is preferably 1 % by mass or more and 50% by mass or less, more preferably 10% by mass or more and 30% by mass or less of the bright pigment dispersion (Y). This makes it easier to suppress the disorder in the arrangement of the glitter material.
  • the second solvent is not particularly limited.
  • the second solvent may be water, an organic solvent, or a combination thereof. Among them, water is preferred from the viewpoint of low VOC.
  • the proportion of water in the second solvent is preferably 50% by mass or more, and preferably 80% by mass or more.
  • Examples of the organic solvent used as the second solvent include the same organic solvents as those exemplified as the first solvent.
  • the amount of the second solvent is not particularly limited, and is appropriately set depending on the solid content, viscosity, etc. of the glitter pigment dispersion (Y).
  • the second solvent for example, has a solid content of 0.1% by mass or more and 10.0% by mass or less of the bright pigment dispersion (Y), and has a type B viscosity of the bright pigment dispersion (Y) at 20°C. It is added so that the viscosity measured by a meter is 20 cps/6 rpm or more and 3000 cps/6 rpm or less.
  • the glitter pigment dispersion material (Y) also contains various additives exemplified as those included in the glitter coating film.
  • a dispersant is added to improve the dispersibility of the glitter material.
  • the dispersant is not particularly limited, and is appropriately selected depending on the second solvent, glitter material, and the like.
  • examples of the dispersant include inorganic dispersants such as phosphates and polyphosphates; polycarboxylic acid-based polyethylene glycol-based systems, naphthalene sulfonic acid-formalin condensation systems, etc. Polymer type dispersants; low molecular type dispersants such as alkyl sulfonic acid type, quaternary ammonium type, and higher alcohol alkylene oxide type are used.
  • examples of phosphates include sodium hexametaphosphate, sodium pyrophosphate, and sodium phosphate.
  • the bright pigment dispersion (Y) is a solvent-based dispersant
  • a polymer-type dispersant such as a polycarboxylic acid partial alkyl ester type, a polyether type, a polyalkylene polyamine type, etc. is used.
  • the amount of dispersant is not particularly limited.
  • the amount of the dispersant may be, for example, 0.01% by mass or more and 3% by mass or less, and 0.1% by mass or more and 1.0% by mass or less of the bright pigment dispersion (Y).
  • a surface conditioner is added to control the surface tension of the glitter coating. This makes it easier for the glitter material to be arranged parallel to the coating film. Furthermore, the adhesion between layers is improved.
  • the surface conditioner is not particularly limited.
  • the surface conditioning agent include silicone-based, acrylic-based, vinyl-based, and fluorine-based surface conditioning agents. These may be used alone or in combination of two or more. Among these, silicone-based surface conditioners are preferred from the viewpoint of the glitter properties and water resistance of the glitter coating film.
  • silicone-based surface conditioners include polydimethylsiloxane and modified silicones obtained by modifying polydimethylsiloxane.
  • modified silicones include polyether modified products, acrylic modified products, and polyester modified products.
  • surface conditioning agents include, for example, the BYK series (manufactured by BYK Chemie), the Tego series (manufactured by Evonik), the Granol series, the Polyflow series (all manufactured by Kyoeisha Chemical Co., Ltd.), and the Disparon series (manufactured by Kusumoto Chemical Co., Ltd.). (manufactured by the company).
  • the amount of surface conditioner is not particularly limited.
  • the amount of the surface conditioning agent is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.2% by mass or more and 8% by mass or less, and 0.4% by mass or more and 6% by mass or less of the bright pigment dispersion (Y). Particularly preferably less than % by mass.
  • the surface conditioner is within this range, the surface tension of the glitter coating film decreases, and the wettability of the glitter pigment dispersion (Y) to the uncured colored coating film tends to improve.
  • Step of forming an uncured clear coating film S13
  • a clear paint (Z) is applied onto the glittering paint film to form an uncured clear paint film.
  • the coating method is not particularly limited. Examples of the coating method include methods similar to those for colored paints. Among these, rotary atomization electrostatic coating is preferred from the viewpoint of coating efficiency.
  • the amount of the clear paint (Z) applied is not particularly limited.
  • the clear paint (Z) is applied, for example, so that the thickness of the clear paint film after curing is 25 ⁇ m or more and 45 ⁇ m or less.
  • the clear paint (Z) is not particularly limited, and conventionally known clear paints can be used.
  • the form of the clear paint (Z) is also not particularly limited.
  • the clear paint (Z) may be powder, water-based, or solvent-based.
  • the clear paint (Z) contains the third thermosetting resin described above.
  • the clear paint (Z) contains a second curing agent, a third solvent, various additives, etc., as necessary.
  • the clear paint (Z) is prepared by diluting a mixture of a third thermosetting resin, a second curing agent, various additives, etc. with a third solvent.
  • the clear paint (Z) may be a one-component paint or a multi-component paint such as a two-component paint.
  • the viscosity of the clear paint (Z) is not particularly limited.
  • the viscosity of the clear paint (Z) measured at 20° C. using a B-type viscometer is, for example, 500 cps/6 rpm or more and 6000 cps/6 rpm or less.
  • the solid content of the clear paint (Z) is not particularly limited.
  • the solid content of the clear paint (Z) is, for example, 40% by mass or more and 60% by mass or less.
  • thermosetting resin The third thermosetting resin is formed from a crosslinkable functional group and a base resin. Details of the crosslinkable functional group and base resin are as described above.
  • the one-component clear paint (Z) contains, for example, polyepoxide and polyacid as the third thermosetting resin.
  • the one-component clear paint (Z) includes, as the third thermosetting resin, an acrylic resin containing an acid anhydride group (1), a polyester resin containing a carboxyl group (2), acrylic resin (3) containing a hydroxyl group and an epoxy group.
  • the acid anhydride group of the acrylic resin (1) may be half-esterified with a low molecular weight alcohol or the like.
  • such a third thermosetting resin will be referred to as an acid-epoxy curing resin composition.
  • the acid epoxy curing resin composition can easily increase the solid content of the clear paint (Z). Furthermore, according to the acid-epoxy curing resin composition, a clear coating film with excellent acid resistance can be easily obtained.
  • the curing of the acid-epoxy curable resin composition progresses as the three types of polymers mentioned above react with each other.
  • the curing mechanism of the acid-epoxy curing resin composition is as follows. First, by heating, the acid anhydride group in the acrylic resin (1) reacts with the hydroxyl group in the polyester resin (2) and the acrylic resin (3) to form a carboxy group. This carboxy group and the carboxy group in the polyester resin (2) react with the epoxy group present in the acrylic resin (3) to form a crosslinking point. A crosslinking reaction occurs starting from this crosslinking point.
  • the blending of the acrylic resin (1), polyester resin (2), and acrylic resin (3) is not particularly limited.
  • the formulation of acid-epoxy curable resin compositions is carried out in amounts and methods well known to those skilled in the art.
  • the molar ratio of the carboxy group possessed by the acrylic resin (1) and the polyester resin (2) to the epoxy group possessed by the acrylic resin (3) is preferably 1/1.4 or more and 1/0.6 or less, More preferably 1/1.2 or more and 1/0.8 or less.
  • the curability of the clear paint (Z) tends to improve.
  • a clear coating film that is resistant to yellowing can be easily obtained.
  • the molar ratio of the carboxy group that the acrylic resin (1) has to the hydroxyl group that the polyester resin (2) and the acrylic resin (3) have is preferably 1/2.0 or more and 1/0.5 or less, and 1/1. More preferably 5 or more and 1/0.7 or less. Thereby, the curability of the clear paint (Z) tends to improve. Furthermore, a clear coating film with excellent water resistance can be easily obtained.
  • a two-component clear paint (Z) is preferable because it easily improves the physical properties of the coating film.
  • the two-component clear paint (Z) includes a separated third thermosetting resin and a second curing agent.
  • the third thermosetting resin and the second curing agent are mixed immediately before use.
  • Examples of the combination of the third thermosetting resin/second curing agent include carboxyl group-containing resin/epoxy group-containing resin, hydroxyl group-containing resin/polyisocyanate compound, hydroxyl group-containing resin/blocked isocyanate compound, and hydroxyl group-containing resin/melamine resin. Can be mentioned. These are particularly suitable for forming clear coatings.
  • the two-component clear paint (Z) may contain a hydroxyl group-containing resin as the third thermosetting resin and a polyisocyanate compound as the second curing agent, since the physical properties of the coating film can be easily improved. preferable.
  • hydroxyl group-containing resin examples include hydroxyl group-containing acrylic resins, hydroxyl group-containing polyester resins, hydroxyl group-containing polyether resins, and hydroxyl group-containing polyurethane resins.
  • hydroxyl group-containing acrylic resins and hydroxyl group-containing polyester resins are preferred, and hydroxyl group-containing acrylic resins are particularly preferred. These may be used alone or in combination of two or more.
  • the hydroxyl value of the hydroxyl group-containing acrylic resin is not particularly limited. From the viewpoint of the scratch resistance and water resistance of the coating film, the hydroxyl value of the hydroxyl group-containing acrylic resin is preferably 80 mgKOH/g or more and 200 mgKOH/g or less, more preferably 100 mgKOH/g or more and 180 mgKOH/g or less.
  • the weight average molecular weight of the hydroxyl group-containing acrylic resin is not particularly limited. From the viewpoint of acid resistance and smoothness of the coating film, the weight average molecular weight of the hydroxyl group-containing acrylic resin is preferably 2,500 or more and 40,000 or less, more preferably 5,000 or more and 30,000 or less.
  • the weight average molecular weight can be calculated from a chromatogram measured with a gel permeation chromatography based on the molecular weight of standard polystyrene.
  • As the gel permeation chromatograph for example, HLC8120GPC (manufactured by Tosoh Corporation) is used.
  • TSKgel G-4000HXL, TSKgel G-3000HXL, TSKgel G-2500HXL, and TSKgel G-2000HXL are used. Chromatography is performed, for example, using tetrahydrofuran as a mobile phase and a differential refractive index detector (RI) as a detector under conditions of a measurement temperature of 40° C. and a flow rate of 1 cc/min.
  • RI differential refractive index detector
  • the second curing agent is not particularly limited, and may be appropriately selected depending on the third thermosetting resin.
  • Examples of the second curing agent include the same curing agents as those exemplified as the first curing agent.
  • a polyisocyanate compound has at least two isocyanate groups in one molecule.
  • the polyisocyanate compound include aliphatic polyisocyanate, alicyclic polyisocyanate, aliphatic polyisocyanate having an aromatic ring not bonded to an isocyanate group in the molecule (araliphatic polyisocyanate), aromatic polyisocyanate, Examples include derivatives of these polyisocyanates.
  • aliphatic polyisocyanates examples include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3- Aliphatic diisocyanates such as butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, dimer acid diisocyanate, methyl 2,6-diisocyanatohexanoate (common name: lysine diisocyanate); 2, 2-isocyanatoethyl 6-diisocyanatohexanoate, 1,6-diisocyanato-3-isocyanatomethylhexane, 1,4,8-triisocyanatooctane, 1,6,11-triisocyanatoundecane, 1, Aliphatic tri
  • Examples of the alicyclic polyisocyanate include 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, and 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (common name: isophorone diisocyanate), 4-methyl-1,3-cyclohexylene diisocyanate (common name: hydrogenated TDI), 2-methyl-1,3-cyclohexylene diisocyanate, 1,3- or 1,4-bis(isocyanatomethyl ) cyclohexane (common name: hydrogenated xylylene diisocyanate) or mixtures thereof, methylene bis(4,1-cyclohexanediyl) diisocyanate (common name: hydrogenated MDI), norbornane diisocyanate, 4,4'-methylene bis(cyclohexyl isocyanate), etc.
  • Alicyclic diisocyanate 1,3,5-triisocyanatocyclohexane, 1,3,5-trimethylisocyanatocyclohexane, 2-(3-isocyanatopropyl)-2,5-di(isocyanatomethyl)-bicyclo( 2.2.1) Heptane, 2-(3-isocyanatopropyl)-2,6-di(isocyanatomethyl)-bicyclo(2.2.1)heptane, 3-(3-isocyanatopropyl)-2 , 5-di(isocyanatomethyl)-bicyclo(2.2.1)heptane, 5-(2-isocyanatoethyl)-2-isocyanatomethyl-3-(3-isocyanatopropyl)-bicyclo(2.
  • araliphatic polyisocyanate examples include methylene bis(4,1-phenylene) diisocyanate (common name: MDI), 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, ⁇ , ⁇ '-diisocyanato-1 , 4-diethylbenzene, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene (common name: tetramethylxylylene diisocyanate) or mixtures thereof; 1,3, Examples include araliphatic triisocyanates such as 5-triisocyanatomethylbenzene.
  • MDI methylene bis(4,1-phenylene) diisocyanate
  • 1,3- or 1,4-xylylene diisocyanate or a mixture thereof ⁇ , ⁇ '-diisocyanato-1 , 4-diethylbenzene, 1,3- or 1,4-bis(1-isocyanato-1-methyleth
  • aromatic polyisocyanates examples include m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and 2,4-tolylene diisocyanate (common name: 2,4-TDI).
  • aromatic diisocyanates such as 2,6-tolylene diisocyanate (common name: 2,6-TDI) or mixtures thereof, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate; triphenylmethane-4, Aromatic triisocyanates such as 4',4''-triisocyanate, 1,3,5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene; 4,4'-diphenylmethane-2,2', Examples include aromatic tetraisocyanates such as 5,5'-tetraisocyanate.
  • polyisocyanate derivatives include the above-mentioned polyisocyanate dimer, trimer, biuret, allophanate, uretdione, uretimine, isocyanurate, oxadiazinetrione, polymethylene polyphenyl polyisocyanate (crude MDI, polymeric MDI), and crude TDI. can be mentioned.
  • the polyisocyanate compounds may be used alone or in combination of two or more.
  • hexamethylene diisocyanate and 4,4'-methylenebis(cyclohexyl isocyanate) are preferred, and derivatives of hexamethylene diisocyanate are more preferred.
  • polyisocyanate compound prepolymers of the above polyisocyanates or derivatives thereof may be used.
  • the prepolymer is obtained by reacting a polyisocyanate or a derivative thereof with a compound capable of reacting with the polyisocyanate under conditions where an excess of isocyanate groups is present.
  • a compound capable of reacting with polyisocyanate or a derivative thereof is a compound having an active hydrogen group such as a hydroxyl group or an amino group. Examples of the above-mentioned compounds include polyhydric alcohols, low molecular weight polyester resins, amines, and water.
  • a blocked polyisocyanate compound may be used as the polyisocyanate compound.
  • the blocked polyisocyanate compound is obtained by blocking the isocyanate groups in the above polyisocyanate or its derivative with a blocking agent.
  • blocking agents include phenol compounds, lactam compounds, alcohols, ethers, oxime compounds, compounds having an active methylene group, mercaptan compounds, acid amide compounds, imide compounds, amine compounds, imidazole compounds, urea compounds, carbamate esters, Examples include imine compounds, sulfites, azole compounds and ketone compounds.
  • phenol compound examples include phenol, cresol, xylenol, nitrophenol, ethylphenol, hydroxydiphenyl, butylphenol, isopropylphenol, nonylphenol, octylphenol, and methyl hydroxybenzoate.
  • lactam compound examples include ⁇ -caprolactam, ⁇ -valerolactam, ⁇ -butyrolactam, and ⁇ -propiolactam.
  • alcohol examples include methanol, ethanol, propyl alcohol, butyl alcohol, amyl alcohol, lauryl alcohol, benzyl alcohol, glycolic acid, methyl glycolate, ethyl glycolate, butyl glycolate, lactic acid, methyl lactate, ethyl lactate, and butyl lactate. , methylol urea, methylol melamine, diacetone alcohol, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.
  • ether examples include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, and methoxymethanol.
  • oxime compounds include formamide oxime, acetamidoxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, benzophenone oxime, and cyclohexane oxime.
  • Examples of compounds having an active methylene group include dimethyl malonate, diethyl malonate, ethyl acetoacetate, methyl acetoacetate, and acetylacetone.
  • Examples of the mercaptan compound include butylmercaptan, t-butylmercaptan, hexylmercaptan, t-dodecylmercaptan, 2-mercaptobenzothiazole, thiophenol, methylthiophenol, and ethylthiophenol.
  • acid amide compounds include acetanilide, acetanisidide, acetotoluide, acrylamide, methacrylamide, acetamide, stearamide, and benzamide.
  • imide compounds examples include succinimide, phthalimide, and maleimide.
  • Examples of the amine compound include diphenylamine, phenylnaphthylamine, xylidine, N-phenylxylidine, carbazole, aniline, naphthylamine, butylamine, dibutylamine, and butylphenylamine.
  • imidazole compound examples include imidazole and 2-ethylimidazole.
  • urea compounds include urea, thiourea, ethyleneurea, ethylenethiourea, and diphenylurea.
  • Examples of the carbamate include phenyl N-phenylcarbamate.
  • imine compounds examples include ethyleneimine and propyleneimine.
  • sulfites examples include sodium bisulfite and potassium bisulfite.
  • azole compounds include pyrazole, 3,5-dimethylpyrazole, 3-methylpyrazole, 4-benzyl-3,5-dimethylpyrazole, 4-nitro-3,5-dimethylpyrazole, 4-bromo-3,5 - Pyrazole or pyrazole derivatives such as dimethylpyrazole, 3-methyl-5-phenylpyrazole; imidazole or imidazole derivatives such as imidazole, benzimidazole, 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole; 2-methylimidazoline, Examples include imidazoline derivatives such as 2-phenylimidazoline.
  • ketone compounds include methyl ethyl ketone and methyl isobutyl ketone.
  • blocked isocyanate compounds include, for example, Duranate (blocked hexamethylene diisocyanate) series (manufactured by Asahi Kasei Corporation), Sumidur BL3175, Desmodur BL3272MPA, Desmodur BL3475 BA/SN, and Desmodur BL3575/1 MPA/SN. , Desmodule BL4265 SN, Desmodule BL5375 MPA/SN, and Desmodule VP LS2078/2 (all manufactured by Bayer).
  • the clear paint (Z) contains a third solvent, if necessary.
  • the third solvent is not particularly limited.
  • the third solvent may be water, an organic solvent, or a combination thereof. Among them, water is preferred from the viewpoint of low VOC.
  • the proportion of water in the third solvent is preferably 50% by mass or more, and preferably 80% by mass or more.
  • Examples of the organic solvent used as the third solvent include the same organic solvents as those exemplified as the first solvent.
  • the amount of the third solvent is not particularly limited, and is appropriately set depending on the solid content and viscosity of the clear paint (Z).
  • the third solvent is added, for example, so that the solid content of the clear paint (Z) is 30% by mass or more and 70% by mass or less.
  • the heating conditions are appropriately set depending on the composition of each coating film.
  • the heating temperature is, for example, 70°C or higher and 150°C or lower, and may be 80°C or higher and 140°C or lower.
  • the heating time may be, for example, 10 minutes or more and 40 minutes or less, and may be 20 minutes or more and 30 minutes or less.
  • Examples of the heating device include drying ovens such as hot air ovens, electric ovens, and infrared induction heating ovens.
  • Thickness of glitter coating film The thickness of the glitter coating film was measured using an electromagnetic film thickness meter (FISCHERSCOPE (registered trademark) MMS PC2, manufactured by Fisher Instruments Co., Ltd.). The average value of five different samples was taken as the thickness of the glitter coating film.
  • FISCHERSCOPE electromagnetic film thickness meter
  • Occupancy rate The multi-layer coating film is imaged from its normal direction using an industrial microscope (ECLIPSE LV150N, manufactured by NICON), and the area corresponding to the bright material and the other areas are binary-valued using image processing software. It became.
  • the area ratio of the glitter material was calculated by setting the area of the observation visual field as 100%.
  • the magnification for imaging was 200x.
  • the observation field was 480 nm vertically and 720 nm horizontally. The average value in five different observation fields was taken as the occupancy rate.
  • Si 15 value Using a multi-angle colorimeter (BYK-mac i, manufactured by BYK-Gardner), light irradiated from a direction tilted 15 degrees with respect to the normal direction of the multilayer coating film was measured.
  • the Si 15 value was obtained by taking an image from the normal direction of the layer coating and analyzing it. The average value of five different samples was taken as the Si 15 value.
  • Example 1 Preparation of object to be coated A zinc phosphate treated steel sheet provided with a cured electrodeposited coating was prepared as an object to be coated.
  • the cured electrodeposition coating film was prepared by electrodepositing "Powernics", a cationic electrodeposition coating composition manufactured by Nippon Paint Co., Ltd., on a zinc phosphate-treated steel plate to a dry film thickness of 20 ⁇ m, and then applying it at 160°C. It was formed by heating for 30 minutes.
  • Viscalex HV-30 manufactured by BASF, polycarboxylic acid-based viscosity modifier, nonvolatile content 30%
  • a viscosity modifier manufactured by BASF, polycarboxylic acid-based viscosity modifier, nonvolatile content 30%
  • the mixture was emulsified using a homogenizer to obtain a monomer pre-emulsion. While stirring the inside of the reaction vessel, the monomer pre-emulsion liquid was added dropwise over 3 hours.
  • an aqueous solution of 1 part of APS (ammonium persulfate) dissolved in 50 parts of water as a polymerization initiator was evenly dropped into the reaction vessel until the dropwise addition of the monomer pre-emulsion was completed. did.
  • the reaction was further continued at 80° C. for 1 hour.
  • an aqueous solution prepared by dissolving 2 parts of dimethylaminoethanol in 20 parts of water was charged into the reaction vessel to obtain a hydroxyl group-containing acrylic resin emulsion with a solid content of 40.6% by mass.
  • the acid value was 20 mgKOH/g
  • the hydroxyl value was 60 mgKOH/g
  • the glass transition temperature (Tg) was 30°C.
  • the solid content was measured according to JIS K 5601-1-2 heating residue measurement method.
  • the acid value was 40 mgKOH/g
  • the hydroxyl value was 110 mgKOH/g
  • the number average molecular weight was 2870
  • the glass transition temperature (Tg) was -3°C.
  • the glass transition temperature (Tg) was measured using a differential scanning calorimeter (DSC220C) manufactured by Seiko Instruments (SII). The measurement conditions were a sample amount of 10 mg, a rising rate of 10°C/min, and a measurement temperature of -20°C to 100°C.
  • the product name "EMR-D4670”, manufactured by Toyo Aluminum Co., Ltd., thickness 0.16 ⁇ m, average particle diameter 8 ⁇ m was used.
  • the solid content of the bright pigment dispersion (Y-1) was 5.5%.
  • (VI) Curing step After the clear coating film forming step (V), heating was performed at 140° C. for 20 minutes to obtain a coated object provided with the multilayer coating film A1.
  • the thickness of the colored coating film was 30 ⁇ m
  • the black and white concealing film thickness of the colored coating film was 60 ⁇ m.
  • the thickness of the glitter coating film was 0.5 ⁇ m.
  • the thickness of the clear coating film was 30 ⁇ m.
  • the multilayer coating film A1 was evaluated as described above. Table 1 shows the results of evaluations (1) to (5). Regarding evaluation (6), the Si 15 value of the multilayer coating A1 was 3.3. Regarding the evaluation (7) of the multilayer coating film A1, 80% or more of the scaly glitter materials were arranged parallel to the surface of the glitter coating film. Regarding the evaluation (8) of the multilayer coating film A1, 80% or more of the scaly glitter materials did not overlap with other scaly glitter materials.
  • Example 1 A coated object having the multilayer coating B1 was obtained in the same manner as in Example 1 except that carbon black was used as the colored paint, and evaluations (1) to (5) were performed. The results are shown in Table 1.
  • Example 2 In the step (IV) of forming a glitter coating film, the procedure was the same as in Example 1, except that the glitter pigment dispersion was applied so that the film thickness of the glitter coating film in the obtained multilayer coating film was 2 ⁇ m. A coated object having the multilayer coating film B2 was obtained, and evaluations (1) to (5) were performed. The results are shown in Table 1.
  • Example 2 A coating with a multilayer coating A2 was prepared in the same manner as in Example 1, except that the following colored paint (X-2), bright pigment dispersion (Y-2), and clear paint (Z-2) were used. The coatings were obtained and evaluated. Table 1 shows the results of evaluations (1) to (5). Regarding evaluation (6), the Si 15 value of multilayer coating A2 was 3.3. Regarding the evaluation (7) of the multilayer coating film A2, 80% or more of the scaly glitter materials were arranged parallel to the surface of the glitter coating film. Regarding evaluation (8) of multilayer coating film A2, 80% or more of the scaly glitter materials did not overlap with other scaly glitter materials.
  • the thickness of the colored coating film was 30 ⁇ m, and the black and white concealing film thickness of the colored coating film was 60 ⁇ m.
  • the thickness of the glitter coating film was 0.5 ⁇ m.
  • the thickness of the clear coating film was 30 ⁇ m.
  • Disparon 4200-10 manufactured by Kusumoto Kasei Co., Ltd., anti-sag/settling agent, oxidized polyethylene
  • Disparon 4200-20 manufactured by Kusumoto Kasei Co., Ltd., Anti-sagging/anti-settling agent, polyethylene oxide
  • BYK-110 manufactured by BYK-Chemie Japan Co., Ltd., pigment dispersant
  • BYK-182 manufactured by BYK-Chemie Japan Co., Ltd., pigment dispersant
  • a monomer mixed solution consisting of 50 parts of butyl acetate was added dropwise through the dropping funnel at a constant rate over 3 hours. After the dropwise addition was completed, stirring was continued for another 30 minutes while maintaining the nitrogen atmosphere and temperature. Thereafter, a mixed solution of 40 parts of butyl acetate and 99 parts of Kayaester-O was added dropwise to the flask through the dropping funnel at a constant rate over 30 minutes. After the dropwise addition was completed, stirring was continued for another 2 hours while maintaining the nitrogen atmosphere and temperature. Thereafter, 20 parts of S-100 and 9 parts of butyl acetate were added to the flask to obtain an acrylic resin. The obtained acrylic resin had a hydroxyl value of 50 mgKOH/g, an epoxy group equivalent of 405 g/eq, and a number average molecular weight of 2,150.
  • Example 7 A coated object having the multilayer coating film B7 was obtained in the same manner as in Example 2, except that carbon black was used as the colored paint, and evaluations (1) to (5) were performed. The results are shown in Table 2.
  • Example 9 In the preparation of the bright pigment dispersion (II-2), a multilayer was prepared in the same manner as in Example 2, except that mica (thickness 1 ⁇ m, average particle diameter 17 ⁇ m) was used in place of the scaly aluminum particles A. A coated object having coating film B9 was obtained, and evaluations (1) to (5) were performed. The results are shown in Table 2.
  • the automobile body and the method for manufacturing an automobile body of the present invention are particularly applicable to the outer panel of an automobile body.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Architecture (AREA)
  • Structural Engineering (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Laminated Bodies (AREA)
  • Body Structure For Vehicles (AREA)

Abstract

L'invention concerne une carrosserie d'automobile et son procédé de fabrication, ladite carrosserie d'automobile présentant à la fois une blancheur et une texture métallique. La carrosserie d'automobile comprend une matière revêtue et un film de revêtement multicouche. Le film de revêtement multicouche est pourvu d'un film de revêtement colorant formé sur la matière revêtue et contenant un pigment blanc, un film de revêtement photoluminescent formé sur le film de revêtement colorant et contenant un matériau photoluminescent, et un film de revêtement transparent formé sur le film de revêtement photoluminescent. Une valeur de luminosité L*45 tombe à l'intérieur de la plage de 70 à 90 est atteinte, ladite valeur de luminosité étant basée sur une réflectivité spectrale obtenue lorsque de la lumière I45 irradiée au niveau de la surface du film de revêtement multicouche sous un angle de 45° est reçue sous un angle de 45° par rapport à de la lumière réfléchie régulièrement. Le rapport L*5/L*15 entre une valeur de luminosité L*5 basée sur une réflectivité spectrale obtenue lorsque la lumière I45 est reçue sous un angle de 5° par rapport à de la lumière réfléchie régulièrement et une valeur de luminosité L*15 basée sur une réflectivité spectrale obtenue lorsque la lumière I45 est reçue sous un angle de 15° par rapport à de la lumière réfléchie régulièrement tombe à l'intérieur de la plage de 1,2 à 2,5. Lorsqu'observée depuis la surface du film de revêtement multicouche, l'occupation du matériau photoluminescent tombe à l'intérieur de la plage de 10 % à 30 %. La granularité de la surface du film de revêtement multicouche tombe à l'intérieur de la plage de 1,0 à 3,0.
PCT/JP2023/016906 2022-05-13 2023-04-28 Carrosserie d'automobile et son procédé de fabrication WO2023219017A1 (fr)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011162732A (ja) * 2010-02-15 2011-08-25 Kansai Paint Co Ltd メタリック塗料組成物及び塗膜形成方法
JP2012170910A (ja) * 2011-02-22 2012-09-10 Kansai Paint Co Ltd 複層塗膜形成方法
JP2016074825A (ja) * 2014-10-07 2016-05-12 関西ペイント株式会社 塗料組成物
WO2017135426A1 (fr) * 2016-02-05 2017-08-10 関西ペイント株式会社 Film de revêtement multicouche et procédé de formation d'un film de revêtement multicouche
WO2020044672A1 (fr) * 2018-08-31 2020-03-05 関西ペイント株式会社 Procédé de formation d'un film de revêtement multicouche
WO2020158222A1 (fr) * 2019-02-01 2020-08-06 関西ペイント株式会社 Film de revêtement multicouche et procédé de formation d'un film de revêtement multicouche

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011162732A (ja) * 2010-02-15 2011-08-25 Kansai Paint Co Ltd メタリック塗料組成物及び塗膜形成方法
JP2012170910A (ja) * 2011-02-22 2012-09-10 Kansai Paint Co Ltd 複層塗膜形成方法
JP2016074825A (ja) * 2014-10-07 2016-05-12 関西ペイント株式会社 塗料組成物
WO2017135426A1 (fr) * 2016-02-05 2017-08-10 関西ペイント株式会社 Film de revêtement multicouche et procédé de formation d'un film de revêtement multicouche
WO2020044672A1 (fr) * 2018-08-31 2020-03-05 関西ペイント株式会社 Procédé de formation d'un film de revêtement multicouche
WO2020158222A1 (fr) * 2019-02-01 2020-08-06 関西ペイント株式会社 Film de revêtement multicouche et procédé de formation d'un film de revêtement multicouche

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